1. Field of the Invention
The present invention relates to an antenna, in particular to a surface mounted planar.
2. Description of Related Art
Wireless communication products have already become a part of our life, which can be installed in car, public communication equipment or a portable communication apparatus. An antenna installed in such communication products is used to receive and emit electromagnetic waves, which couples electromagnetic energy between free space and guiding device as a basic function. Many different kinds of antennas such like dipole antenna, planar antenna and micro stripe antenna are developed to meet requirements from different kinds of communication products.
FIGS. 1(a) and 1(b) show a prior art pin through hole type planar antenna 10, which includes a ceramic base 101, a radiation metal plate 102 arranged on a top face of the ceramic base 101, and a ground metal plate 103 arranged on a bottom face of the ceramic base 101. Further, a through hole 104 is formed from the radiation metal plate 102 through the ceramic base 101 to the ground metal plate 103 and is used to accommodate a T-shaped signal feeder 105 to form a planar antenna structure which is able to mount on a mother board. But this kind of pin through hole type planner planar antenna 10 needs to be manually mounted onto the mother board instead of using automatic machine.
Moreover, a surface mounted patch antenna 30 as FIGS. 2(a) and 2(b) show, includes a ceramic base 301, a radiation metal plate 302 arranged on a top face of the ceramic base 301, a ground metal plate 303 arranged on a bottom face of the ceramic base 301, and at least one metal electrode 304 arranged on a lateral side face of the ceramic base 301. This kind of patch antenna 30 can be mounted onto the mother board by using automatic machine. However, uniform welding temperature is difficult to achieve for ceramic base 301 with considerable size due to temperature characteristics in surface mount process. This makes surface mounting process troublesome for the surface mounted patch antenna 30.